High Value Organic-Enhanced Inorganic Fertilizers

ABSTRACT

The invention is directed to manufacture of fertilizer having commercial levels of nitrogen supplemented with organic substances. The process treats organic matter with acid causing hydrolysis of organic polymers after which the mix is injected with nitrogen. The resultant sterilized and liquefied organic matter is disbursed over recycled material for the production of granules. Because the process allows for the controlled addition of acids and ammonia, desired levels of components can be achieved. The process is scalable, odor controlled and safe thereby allowing for the location of biosolid processing facilities in most any location. Further, the fertilizer of the invention provides a dual nitrogen-release profile when applied to crops. After application to soil, fertilizer of the invention releases an immediate bolus of nitrogen, similar to traditional ammonium sulfate, followed by continued slow release of nitrogen typically over a season.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/432,709 filed Mar. 28, 2012, which issued as U.S. Pat. No. 8,992,654on Mar. 31, 2015 and claims priority to U.S. Provisional Application No.61/468,157 filed Mar. 28, 2011, U.S. Provisional Application No.61/569,007 filed Dec. 9, 2011, and U.S. Provisional Application No.61/615,258 filed Mar. 24, 2012, and a continuation-in-part of U.S.application Ser. No. 13/104,127 filed May 10, 2011, which is pending andis a continuation of U.S. application Ser. No. 12/033,809 filed Feb. 19,2008, which issued as U.S. Pat. No. 7,947,104 May 24, 2011, and claimspriority to U.S. Provisional Application No. 60/890,422 filed Feb. 16,2007, all of which are specifically and entirely incorporated byreference.

BACKGROUND

1. Field of the Invention

This invention is directed to methods, systems, and processes for themanufacturing of fertilizer and the fertilizer product manufactured bythese methods. In particular, the invention is also directed to themanufacture of fertilizers with predetermined concentrations or absencesof nitrogen, phosphate and/or potassium.

2. Description of the Background

Sludge today is estimated to be produced at a rate of over 8 million drymetric tons annually or roughly about 64 dry pounds of biosolids forevery individual in the United States. The term sludge has been replacedwith the term biosolid which includes all forms of municipal wastes suchas, for example, domestic septage, farm and factory organic wastes thatare collected or otherwise find their way to waste-water treatment,sewer run offs, pharmaceutical wastes including fermentation andprocessing wastes, microbial digests, food wastes and food byproducts,animal manures, digested animal manures, organic sludge, organisms andmicroorganisms and all combinations thereof. Most all industrial wastesfind their way into municipal sludge or are otherwise disposed of inlandfills or as may be common in the particular industry. As can beenvisioned, all forms of discarded material can and typically do wind upin municipal sludge including biologically-active molecules such aspharmaceuticals as well as their metabolized products, paper, plastics,metals and most all forms of garbage.

Biosolids are collected typically by municipalities through existinginfrastructures such as sewers and other types of residential andindustrial plumbing systems. Collected material is sent to one or morecentral facilities referred to as waste-water treatment plants. At theseplants water is separated from the solids and sent through purificationprocedures for reclamation. The solids are either burned or transportedby truck for burial or by barge for dumping into the ocean. Burning orincineration has become more common in part because of the awareness thedangers of unprocessed biosolids. In all biosolids are assumed to be notonly harmful chemicals but also bioactive compounds, and pathogens.Federal, state and local regulations exist that strictly control thehandling of biosolids for the safety of both workers and the public. Butwhether burned or buried, such procedures are highly inefficient andextremely costly.

Burning destroys most of the harmful materials present in the biosolids,but the cost in damage to the environment is always tremendous.Incinerators have been built specifically to deal with municipal waste.These incinerators create huge amounts of contaminated smoke spoilingthe air within hundreds of square miles around the facility. The smokethat's emitted contains whatever contaminants as were present in thebiosolids such as metals and other non-combustible components. Thosecontaminants settle onto fields and bodies of water creating ecologicalnightmares around the plants and sometimes for great distances down-windof the plants. Although burning can produce energy, energy production ishighly inefficient requiring huge amounts of biosolids to become costeffective. The amount of energy produced is always small in comparisonto the amount of material incinerated. Even after burning, enormousamounts of soot remain that must be removed and disposed. As compared tothe original biosolid, the soot is devoid of any positive impact to theenvironment whatsoever and is simply and unceremoniously buried ordumper into the ocean. Overall burning negatively increases the impactof biosolid disposal to the environment and for many years into thefuture.

Biosolids that have been treated to some degree of processing areclassified according to federal standards established by the UnitedStates Environmental Protection Agency as Class A or Class B. “Class A”biosolids are considered free of detectable pathogens and sufficientlysafe as a fertilizer for animal or human crop usage. Pathogens such as,for example, Salmonella sp. bacteria, fecal coliform indicator bacteria,enteric viruses, and viable helminth ova are below detectable levels.When pathogens can be detected in the biosolids, the USEPA has classedsuch treated biosolids as “Class B” implying that they are of a lowerstandard than the “Class A” treated biosolids. Because Class B biosolidscontain pathogen indicators—and therefore potential pathogens, they arerestricted in the manner by which they can be applied to animal andhuman crops.

The Part 503 rule (Title 40 of the Code of Federal Regulations, Part503, incorporated herein by reference) lists six alternatives fortreating biosolids so they can be classified in Class A with respect topathogens. Alternative 1 requires biosolids to be subjected to one offour time-temperature regimes. Alternative 2 requires that biosolidsprocessing meets pH, temperature and air-drying requirements.Alternative 3 requires that when biosolids are treated in otherprocesses, it must be demonstrated that the process can reduce entericviruses and viable helminthes ova, and operating conditions used in thedemonstration after pathogen reduction demonstration is completed mustbe maintained. Alternative 4 requires that when treated in unknownprocesses, biosolids be tested for pathogens at the time the biosolidsare used or disposed or, in certain situations, prepared for use ordisposal. Alternative 5 requires that biosolids be treated in one of theProcesses to Further Reduce Pathogens. Alternative 6 requires thatbiosolids be treated in a process equivalent to one of the Processes toFurther Reduce Pathogens, as determined by the permitting authority.

Class A pathogen biosolids must also possess a density of fecal coliformof less than 1,000 most probable numbers (MPN) per gram total solids(dry-weight basis) or a density of Salmonella sp. bacteria of less than3 MPN per 4 grams of total solids (dry-weight basis). Either of thesetwo requirements must be met at one of the following times: when thebiosolids are used or disposed; when the biosolids are prepared for saleor give-away in a bag or other container for land application; or whenthe biosolids or derived materials are prepared to meet the requirementsfor Exceptional Quality biosolids.

All biosolids applied to the land must meet the ceiling concentrationfor pollutants, comprising ten heavy metal pollutants: arsenic, cadmium,chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc.If a limit for any one of these is exceeded, the biosolids cannot beapplied to the land without the incorporation of significantrestrictions. Exceptional Quality (EQ) is a term used by the USEPA GuidePart 503 Rule 7 to characterize biosolids that meet low-pollutant andClass A pathogen reduction (virtual absence of pathogens) limits andthat have a reduced level of degradable compounds that attract vectors.

Biosolids that are merely dried have several disadvantages foragricultural use. Biosolids have a low fertilization value, typicallyhaving nitrogen content of only about two to five percent. Volume islarge and costs per unit of nitrogen are high. The heat-dried biosolidsoften have a disagreeable odor, particularly when moist. Also, driedpellets have low density and hardness and when blended with othercommercial fertilizer materials, the pellets may segregate, anddisintegrate and may not spread on the field uniformly with other moredense ingredients. The disagreeable odor associated with the use ofbiosolids, unless adequately treated, will continue to be present duringfurther processing of a nitrogen rich fertilizer product, and cancontinue to be present in the final product. This complicates theplacement of suitable fertilizer processing plants to locations that arenot in close proximity to residential communities. Additionally, thelonger distance that biosolids must be transported adds to the cost andlogistics of disposing of this waste product. Another disadvantage tocurrent biosolids-enhanced fertilizers is that bacterial action maycontinue when the material becomes moist, and under storage conditions,the material's temperature may rise to the point of auto-ignition.Hence, except for special markets that value its organic content forsoil amendment or filler in blended fertilizer, there is relatively poordemand for the heat-dried biosolids product. In many casesmunicipalities must pay freight charges, or may offer other incentivesfor commercial growers to use the material. However, this is frequentlystill more economical than alternative disposal schemes.

The market value for agricultural fertilizers is principally based ontheir nitrogen content. A need exists for a practical, safe and economicmethod for increasing the nitrogen content of biosolids to a levelapproaching that of commercial mineral fertilizers, e.g., eight totwenty-two percent. If such a biosolids fertilizer could bemanufactured, then the overall value of the biosolids product and demandfor the product would likely increase. Moreover, a properly manufacturedbiosolids fertilizer will have an advantage in that much of its nitrogenwill be of the slow release type. Slow-release or controlled releasefertilizer is one in which the nutrient, e.g., nitrogen as in ammoniumions, phosphate and/or sulfate, becomes available in the soil column atrates slower than fast-available nutrients as from traditionalfertilizers such as urea, ammonium sulfate and diammonium phosphate.This slower action and/or prolonged availability of the nutrient in thesoil column is very desirable and provides nutrients to the plantthroughout the plant growing cycle with the implication that lessnitrogen needs to be applied to the soil or crop thereby reducing thepotential of environmental contamination and reducing the cost offertilizer usage. Traditional inorganic manufactured slow releasenitrogen fertilizers have a price many times that of ordinary mineralnitrogen fertilizers. Under the scenario of high nitrogenbiosolids-containing fertilizer production from their biosolids,municipalities would enjoy public and regulatory support for theirbiosolids disposition program. Such a program would ensure the regularremoval of their dewatered or dried biosolids, for example, by recyclingbiosolids into a high nitrogen fertilizer which then can be solddirectly into the mature national fertilizer distribution industry,thereby eliminating one of the major problems traditionally associatedwith biosolids treatment programs.

Prior attempts have been made to reach some of these objectives. U.S.Pat. Nos. 3,942,970, 3,655,395, 3,939,280, 4,304,588, and 4,519,831describe processes for converting sewage biosolids to fertilizer. Ineach of these processes a urea/formaldehyde condensation product isformed in situ with the biosolids. Thus, the processes require thehandling of formaldehyde, a highly toxic lachrymator and suspectedcancer-causing agent.

Other processes require costly process equipment and/or specialconditions not readily incorporated in existing sewage treatmentfacilities (see, Japanese Patent No. 58032638; French Patent No.2,757,504).

A simple method for increasing the nitrogen in bio solids would be toblend commercial nitrogen fertilizer materials to the wet biosolidsprior to drying and pelletizing. There are only a few high-nitrogenfertilizer materials that are economical for use in agriculture.Examples include: ammonia (82 wt. percent N), urea (46 wt. percent N),and ammonium nitrate (33.54 wt. percent N). Ammonia has high volatilityand is subject to strict regulation of discharges to the atmosphere.Urea is a solid that adsorbs moisture quite readily and makes the sludgemore difficult to dry. Urea is also highly susceptible to breakdown toammonia by the microbes and enzymes in biosolids if they are notproperly prepared, resulting in nitrogen loss and an odor problem.Ammonium nitrate is a strong oxidizer and can result in a potentialexplosion problem which has all but eliminated this fertilizer from thecommercial market after 2000. All of these fertilizers have highnitrogen content, but are less than ideal for combining with biosolidsabsent special processing.

Other references, such as European Patent No. 0143392, Japanese PatentNo. 9110570 A2, and “Granulation of Compost from Sewage Sludge. V.Reduction of Ammonia Emission from Drying Process”, Hokkaidoritsu KogyoShikenjo Hokoku, 287, 85-89 (1988) fail to disclose the use of acidswith ammonium sulfate additions and do not discuss the issue ofcorrosion of steel process equipment under acid conditions.

Over the past thirty years, alkaline stabilization of biosolids has beena standard and successful method of making biosolids into beneficiallyuseful materials that can be used principally as soil-conditioningmaterials. Because these alkaline stabilized biosolids products havehigh calcium carbonate equivalencies, they have been produced andmarketed as Agricultural liming or Ag-lime materials, usually as areplacement for calcium carbonate in farm soil management strategies.Because of this usage, the value of these materials has been restrictedto only a few dollars per ton of product. However, transportation costsare high in large part due to the significant water content of thematerial. Amounts of water up to fifty percent render transportationeconomically and geographically restricted to areas close to the sourceof their treatment.

Thus, there is a long standing need for practical means of increasingthe economic value of sewage biosolids through increasing its nitrogencontent, and increasing the ability to be spread as well as a need totreat these materials such that they are converted into commodityfertilizers with physical and chemical and nutrient properties such thatthey can command significant value in the national and internationalcommodity fertilizer marketplace. A series of U.S. patents, U.S. Pat.Nos. 5,984,992; 6,159,263; 6,758,879 and 7,128,880 describe methods ofproduction of high nitrogen organically enhanced ammonium sulfatefertilizers made with biosolids utilizing a pipe-cross reactor asoriginated by the Tennessee Valley Authority. The pipe, tee andpipe-cross reactor are defined by the IFDC in the Fertilizer Manual(1998), p 440 as: “the pipe reactor consists basically of a length ofcorrosion-resistant pipe (about 5-15 m long) to which phosphoric acid,ammonia and often water are simultaneously added to one end through apiping configuration resembling a tee, thus the name ‘tee reactor.’” Thetee reactor was modified by TVA to also accept an additional flow ofsulfuric acid through another pipe inlet located opposite the phosphoricacid inlet, giving the unit a “cross” configuration and thus the name“pipe-cross reactor”.

Both the IFDC Fertilizer Manual (1998) and the Fertilizer Technical DataBook (2000) refer to the pipe-cross reactors. Pipe-cross reactorsdeliver a concentrated mix to the granulator shaping device and moreefficiently evaporate undesired water from the fertilizer mix than otherdevices, but these references demonstrate a long-felt need forimprovement, indicating that one of the shortcomings of the pipe-crossreactor is scale formation inside the pipe which can result in clogging.

The methodologies taught by this group of patents (U.S. Pat. Nos.5,984,992; 6,159,263; 6,758,879 and 7,128,880) are plagued by problemsrelated to the pluggage of these narrow (relative to their length)“pipe-cross” reactor configurations, the very short duration of reactiontime in such “pipe-cross” reactors and the difficulty of control of thereaction temperature and pressure and retention time of the mix withinsuch pipe-cross reactors. These pipe-cross reactors are narrow incontrast to their length, e.g., up to six to eight inches in diameterand often fifteen feet in length or longer. The plant practicing themanufacture of organically-enhanced ammonium sulfate fertilizers oftenhad to shut down and disassemble the pipe-cross reactor either due toblockage from biosolids buildup or from destructive over heating in suchreactors such that the commonly used Teflon® coating on theinterior-reaction side of the reactor was melted and ruined. Further,the use of the pipe-cross reactor has the distinct disadvantage ofhaving very short reactor retention times (usually less than twentyseconds) which is an advantage in the manufacture of traditionalfertilizers like ammonium sulfate but is a disadvantage when coupled tothe simultaneous processing of biosolids. Such short processing timeincreases the probability of untreated or non-homogenous mixing as thethree material inputs pass through this reactor. Also limiting is thelack of control over the atmospheric pressure within such pipe-crossreactors since these reactors have open-ended discharges usuallydirectly into a granulator. Related to but distinct from the lack ofcontrol of internal pressures, pipe-cross reactors also have little tono temperature control over the mix passing through the reactor.

U.S. Pat. No. 4,743,287 to Robinson describes a method to use tworeaction vessels in sequence to incorporate organic biosolids intonitrogen fertilizers of low or medium nitrogen concentration (a range offour weight-percent nitrogen to a maximum of nitrogen concentration often weight-percent). Robinson uses his first reaction vessel to achievevery low pH values of the mixture (pH 0.2 to 1.5) to achieve hydrolysisof molecules present and to prepare the mix for reaction in a secondreaction vessel. Robinson does indicate that a single reactor can beused, but only in a batch configuration and not in a continuous flowmanufacturing method. Robinson also indicates that the acid and ammoniamay not be injected in any order, but must be injected in sequence. Thispatent describes the reaction vessels capable of achieving highpressures (30 psig) with relatively long retention times as compared tothe pipe-cross reactors. However, Robinson fails to meet the need for anovel and practical continuous flow method of manufacturing highnitrogen (greater than 8 wt. percent nitrogen) and biosolids-containingfertilizer products under the advantages of defined temperatures,pressures and reaction retention times. Thus, an urgent need exists foran effective, efficient, and economical process for treating biosolids.

SUMMARY OF THE INVENTION

The present invention overcomes the problems and disadvantagesassociated with current strategies and designs, and provides new toolsand methods for the manufacture of fertilizers.

One embodiment of the invention is directed to methods for manufactureof a fertilizer comprising: providing an organic material thatpreferably contains biosolids, wherein the organic material has a solidscontent of at least ten percent; optionally adding an odor control agentto the organic material to create a mixture; adding an acid to themixture under a first pressure and elevated temperature for a firstperiod of time forming a liquefied mixture; adding ammonia to theliquefied mixture under a second pressure and elevated temperature for asecond period of time; and processing the liquefied mixture to form thefertilizer. The phrase organic material includes all biosolids, but isnot limited to biosolids such as organic biosolids, biosolids containingmicroorganisms, municipal biosolids or heat-dried biosolids, and alsoincludes pharmaceutical and laboratory processing and fermentationwastes, farm and agricultural wastes, decayed and digested organicmaterials, harvested plants including farmed crop materials such asroughage and silage of corn and soybean plants as well as wheat, riceand barley plants, algae and cyanobacteria that may be harvested fromponds and other bodies of water, bacteria, mold and fungi, industrialwastes and their by-products, microbial, chemical and enzymatic digestsof organic products, plant and animal foods, food stuffs, andbyproducts, recycled fertilizers, and all combinations thereof. Anelement of the invention is that the organic material that containsplastic and hair and similar material does not need to be removed priorto processing. Preferably, the organic material is dewatered or hydratedto a solids content of between 15 and 40 percent, more preferably theorganic material has a percent dryness of 22 percent or less. Also, aportion of the organic material may be dewatered to a dryness greaterthan 70 or 85 percent, and blended with the remaining portion of theorganic material to achieve a desired percent dryness. Preferably, theorganic material is hydrated with process water recovered from one ormore steps of the method.

Optionally, odor control agents may be added to the organic material.Preferred odor control agents include, but are not limited to one ormore of calcium ferrate, sodium ferrate, potassium ferrate, ferroussulfate heptahydrate, rozenite, melanterite, ferric chloride, ferroussulfate, ferrous sulfate monohydrate, hydrogen peroxide, ozone andsalts, derivatives and combinations thereof, as well as various saltsthereof. Preferably, the mixture of the organic material with the odorcontrol agent forms a thixotropic mixture and the mixture is heatedprior to the addition of acid. Also preferably, heating is performed ina first pressure vessel and the first pressure is maintained at between20 and 60 psig, the first temperature is between 66° C. (150° F.) and127° C. (260° F.), and the first period of time is between 3 minutes and30 minutes. More preferably, the first temperature may be between 93° C.(200° F.) and 121° C. (250° F.) and the first period of time may bebetween 5 minutes and 10 minutes. Preferably the viscosity of theacidified and heated mixture is about 4,000 cP or less. The acid addedto the mixture is preferably a phosphoric acid, a sulfuric acid, or acombination thereof. After acidification, the liquefied mixture istransferred to a second pressure vessel and, preferably, ammonia isheated under pressure to form a gas prior to being added to theliquefied mixture. The preferred second temperature is between 121° C.(250° F.) and 199° C. (390° F.), the preferred second period of time isbetween 1 minute and 30 minutes, and the preferred pressure within thesecond pressure vessel is maintained at between 50 and 200 psig. Theviscosity of the ammoniated mixture is preferably about 1,000 cP orless. Processing of liquefied mixture comprises forming the usablefertilizer. Preferably, the processing comprises drying the combinationto a solids content of greater than 92 percent, or more preferably to asolids content is at least 98 percent. One or more hardening agents maybe added during processing such as, for example, ligno-sulfonate,molasses, alum or a combination thereof. Preferably processing isperformed in a granulator to form granules and the granules are sizedand granules of between 0.5 and 4 mm selected. Preferably, granules ofgreater than 4 mm are further crushed, and combined with granules ofless than 0.5 mm and both are added during processing. An element of theinvention is that each step of the method can be performed in acontinuous process without interruption, although batch processing isalso possible. The processes of the invention preferably also comprise adust control system that collects and recycles dust material createdfrom the processing.

Another embodiment of the invention is directed to fertilizermanufactured by the methods of the invention. Fertilizer will typicallycontain hydrolyzed polymers of one or more of plastics, pharmaceuticalcompounds, antibiotics, hormones, hormone-like molecules, biologicallyactive compounds, macromolecules, carbohydrates, nucleic acids, fats,lipids, proteins, and microorganisms that are present in the biosolids.Preferably the hydrolyzed polymers are amino acids, most of which arenot destroyed during the method of processing, that supplement andsubstantially increase the value of the fertilizer. Preferably,fertilizer of the invention has a nitrogen content of between 6 and 20percent, a phosphate content of between 0 and 10 percent, a potassiumcontent of between 0 and 5 percent, a sulfur content of between 10 and30 percent, an iron content of between 0 and 10 percent, and an organiccontent of between 5 and 30 percent. Also preferably, the fertilizer hasno or almost no unpleasant or disagreeable odors.

Another embodiment of the invention is directed to processes formanufacture of a fertilizer with a predetermined content of one or moreof nitrogen, phosphate and potassium comprising: providing an organicmaterial containing biosolids wherein the organic material has a solidscontent of at least ten percent; optionally adding an odor control agentto the organic material to create a mixture; heating the mixture under afirst pressure to a first temperature for a first period of time; addingan amount of a predetermined acid to the heated mixture, therebycreating an exothermic reaction and forming a liquefied mixture; addinga predetermined amount of ammonia to the liquefied mixture under asecond pressure and heating the mixture to a second temperature forsecond period of time, wherein the amount of ammonia added is determinedfrom the composition of the organic material; and processing theliquefied mixture to form the fertilizer with a predetermined content ofone or more of nitrogen, phosphate and potassium. The process of theinvention may optionally further comprise adding one or more plantnutrients to during processing. Such plant nutrients that can be addedinclude, but are not limited to one or more of urea, ammonium nitrate,ammonium sulfate, monoammonium phosphate, diammonium phosphate, ureaammonium nitrate, liquid urea, potash, iron oxide, soluble iron,chelated iron and combinations thereof. The process preferably furthercomprises adding and one or more hardening agents during processing suchas, for example, ferric oxides, alum attapulgite clay, industrialmolasses, lignin, ligno sulfonate, urea formaldehyde polymerizer andcombinations thereof.

Another embodiment of the invention is directed to systems for themanufacture of a fertilizer comprising: a mixer that blends biosolidswith an odor control agent; a first reaction or pressure vessel whereinthe blended biosolids are mixed with an acid and heated to a firstpredetermined temperature and pressurized to a first predeterminedpressure for a period of time forming a liquid; a second reaction orpressure vessel wherein the liquid is mixed with ammonia from an ammoniasource and heated to a second predetermined temperature and pressurizedto a second predetermined pressure for a second period of time; and agranulator wherein the ammoniated liquid is mixed with preformedgranules and heated to form dried granules of the fertilizer. Preferablythe ammonia source is liquefied or gaseous ammonia under pressure andthe first and second reaction or pressure vessels each contain anagitator. The systems may also include a screening process to selectproduct sized fertilizer granules, and one or more a cooling and coatingapparatus to reduce temperature and control dust prior to storage.Optionally, the cooler may include an ozone generator that providesozone to the cooling fertilizer to eliminate or at least substantiallyreduce disagreeable odors. Preferably, systems also comprise a conveyerfor transporting biosolids to the mixer and another conveyer fortransporting the blended biosolids to the first reaction or pressurevessel; a pressurized piping system that transports acidified biosolidsfrom the first reaction or pressure vessel to the second reaction orpressure vessel, ammonia into the second reaction or pressure vessel;and disperses the ammoniated liquid to the granulator. Preferred systemsfurther comprise one or more screens for selecting granules of apredetermined size and a rotary cooler for cooling and polishing thesized granules, and both a dust control apparatus that collects andrecycles dust from the granulator and a water recovery system wherebywater extracted from biosolids during processing is recovered andrecycled. In certain embodiments, the first and/or second reaction orpressure vessel may be a pipe-cross reactor, or both reaction orpressure vessels are pipe-cross reactors. The process may be performedas a continuous or batch process.

Another embodiment of the invention is directed to methods formanufacture of a product comprising: providing an organic materialwherein the organic material has a solids content of at least tenpercent; adding an acid to the organic material under a first pressureand elevated temperature for a first period of time forming a liquefiedmixture; adding ammonia to the liquefied mixture under a second pressureand elevated temperature for a second period of time; and processing theliquefied mixture to form the fertilizer. Preferably the organicmaterial is plant or bacterial material and, also preferably, the plantor bacterial material is algae, bacteria, fungi or a combinationthereof. Preferably there are toxic materials present in the organicmaterials that are hydrolyzed or otherwise rendered nontoxic orinactivated by the process of the invention. Preferably the firstpressure is between 20 and 60 psig, the elevated temperature is between66° C. (150° F.) and 127° C. (260° F.) and the first period of time isbetween 3 minutes and 30 minutes. Also preferably, the second pressureand elevated temperature for a second period of time are, respectively,between 50 and 200 psig and between 121° C. (250° F.) and 199° C. (390°F.), between 1 minute and 30 minutes. Preferably the product is afertilizer.

Another embodiment of the invention is directed to fertilizermanufactured by the methods of the invention. Preferably, fertilizers ofthe invention have both fast and slow nitrogen release profiles so thata percentage of available nitrogen is released to the soil uponapplication of the fertilizer, preferably from 10 percent to 70 percent,and a second, slower release representing about 30 percent to 90 percentof the available nitrogen content of the fertilizer releases into thesoil over a period of week and months. Preferably, nitrogen release istimed to match the needs of the growing crops or plants.

Other embodiments and advantages of the invention are set forth in partin the description, which follows, and in part, may be obvious from thisdescription, or may be learned from the practice of the invention.

DESCRIPTION OF THE FIGURES

FIG. 1A is directed to portions of the Biosolid Fertilizer Plant FlowChart of one embodiment of the Invention.

FIG. 1B is directed to portions of the Biosolid Fertilizer Plant FlowChart of one embodiment of the Invention.

FIG. 1C is directed to portions of the Biosolid Fertilizer Plant FlowChart of one embodiment of the Invention.

FIG. 2A is directed to portions of the Biosolid Fertilizer Plant FlowChart of another embodiment of the Invention.

FIG. 2B is directed to portions of the Biosolid Fertilizer Plant FlowChart of another embodiment of the Invention.

FIG. 2C is directed to portions of the Biosolid Fertilizer Plant FlowChart of another embodiment of the Invention.

FIG. 3. Schematic of a modified Ammonium Sulfate Process.

FIG. 4. Physical and chemical characteristics of organically modifiedammonium sulfate fertilizer of one embodiment of the invention.

FIG. 5. Nitrogen release curve of ammonium sulfate fertilized plantsshowing percent nitrogen released into soil over number of weeks.

FIG. 6. Nitrogen release curve showing percent nitrogen released intosoil over number of days for ammonium sulfate (AS), organically-modifiedammonium sulfate of the invention (VITAG), and conventional biomass(MILORGANITE).

FIG. 7. Academic nitrogen release curve of plants fertilized withammonium sulfate, organically-modified ammonium sulfate of theinvention, and biosolids showing percent nitrogen released into soilover number of weeks.

DESCRIPTION OF THE INVENTION

All countries and population regions around the world create waste inthe form of organic materials. The phrase organic material includes, butis not limited to biosolids such as organic biosolids, biosolidscontaining microorganisms, municipal biosolids and heat-dried biosolids,and also includes pharmaceutical and laboratory processing andfermentation wastes, farm and agricultural wastes, decayed and digestedorganic materials, harvested plant and plant-like materials such asalgae including blue/green algae, bacteria including blue/greenbacteria, cyanobacteria (e.g., blue/green, rust, black), mold and fungi,industrial wastes and their by-products, microbial, chemical andenzymatic digests of organic products, plant and animal foods, foodstuffs, and byproducts, animal manures, digested and processed animalmanures, recycled fertilizers, and all combinations thereof. Disposal oforganic waste materials pose a major problem as well as expense to allcommunities. Traditional disposal methods involve burial, burial at seaor incineration. Each of these options compounds the problem by creatinguntenable amounts of pollution that foul the community as well as theplanet. New techniques have been developed that involve heat treatmentto inactivate microorganisms and other potentially contaminants that canresult in a product that can be as a low value fertilizer. Althoughthese techniques are ecologically sound, they have not caught onbecause, in large part, the product is of such low value that there islittle to no commercial incentive for communities to switch from thetraditional bury and burn philosophy, and no funds that allow for thecreation of safe processing facilities.

It has been surprisingly discovered that high-value fertilizer can beefficiently manufactured from organic materials, including but notlimited to, raw and semi-processed biosolids, agricultural materials andindustrial wastes. The process of the invention destroys not only allpotentially harmful microorganisms, but hydrolyzes many polymersincluding forms of biopolymers (e.g., DNA, proteins, carbohydrates,toxins, antibiotics, hormones, etc.), forms of composite materials, andeven forms of plastics. The resulting fertilizer product is of highvalue and also contains the hydrolyzed monomers (e.g. amino acids,sugars, etc.) that are beneficial and desirable for a fertilizer. Theprocess of the invention also allows for the production of fertilizerwith pre-selected amounts of each of the components of the fertilizerincluding, but not limited to, the concentrations of nitrogen,phosphorous, potassium, sulfur, iron and organics.

One embodiment of the invention is directed to methods for themanufacture of a fertilizer. A schematic of the general process of theinvention is depicted by FIG. 3. The method comprises providing anorganic material which may contain biosolids or another organic materialto which, optionally, is added an odor control agent, that itself can beutilized as an important plant nutrient in the final fertilizer product,to reduce or eliminate odors that may be present from the organicmaterial or other components of the starting materials. The resultingmixture, which may contain added water recycled from other steps of themethod, is thoroughly mixed and heated to a predetermined temperaturefor a period of time prior to commencing the critical acid/basereactions that occur in a reaction or hydrolysis vessel. To this heatedmaterial is added an acid that reacts exothermically with the organicmaterial and increases both temperature and pressure. During this time,preferably two to ten minutes, the components are mostly or entirelyliquefied. To the heated liquefied material, which optionally may betransferred to a second pressure vessel, is added ammonia, which ispreferably also liquefied or vaporized and also under pressure, and thesubsequent reaction with the acid component of the mixture serves tofurther increase temperature and pressure. The ammoniated and liquefiedbiosolids are maintained for a short period of time under theseconditions, preferably two to ten minutes, and then processed,preferably into granules of fertilizer.

The ammoniation reaction may be carried out to completion whereby all ornearly all of the acid is reacted such that little to no residual acidremains. The combination of nearly all of the acid produces a salt or asalt melt (a partially ammoniated mix) (e.g. with sulfuric acid the saltproduced is ammonium sulfate). Preferably, upon ammoniation salt to meltratios are about 20/80, about 25/75, about 30/70, about 35/65, about40/60, about 45/55, about 50/50, about 55/45, about 60/40, about 65/35,about 70/30, about 75/25, and about 80/20. Salt formation may bedetermined and in real time by the measurement of the pH of the mixture.Preferred pH values are between 6.2 and pH 7.0. Alternatively, it issometimes preferable to partially ammoniate the acid mixture in thereactor and complete the ammoniation in a second pugmill or in thegranulation process.

An advantage of this invention is that, because the organic materialsare liquefied, the liquid can be more easily transported as neededthrough pipes preferably using pressure differentials as compared withany solid, semisolid or thixotropic material. The liquefied organicmaterials can also be more evenly applied to acceptor material in thegranulator thereby permitting the formation of a more evenly formedspherically-shaped granule. Biosolids are preferably entirely liquefied,although mostly liquefied is typically sufficient. Preferably the liquidexhibits a characteristic readiness to flow, little or no tendency todisperse, and relatively high incompressibility.

Viscosity of the starting organic material is typically in excess of100,000 cP and typically 150,000 cP at ambient temperature and does notchange significantly even at elevated temperatures typical in aprocessing facility. For comparative purposes, at about roomtemperatures, molasses has a viscosity of about 5,000 to 10,000 cP,honey has a viscosity of about 2,000 to 10,000 cP, chocolate syrup has aviscosity of about 900 to 1,150 cP, and olive oil has a viscosity ofabout 81 cP. With the addition of acid and heat according to invention,viscosity of the organic material decreases to a range of from about1,000 to 10,000 cP, and preferably to less than 4,000 cP, morepreferably to less than 3,000 cP, more preferably to less than 2,000 cP,and more preferably to less than 1,000 cP. With the addition of ammoniaand the added temperature increase from the resulting exothermicreaction, viscosity decreases to a range of 500 to 4,000 cP, andpreferably to 2,000 cP or less, more preferably to 1,000 cP or less, andmore preferably to 750 cP or less, and more preferably to 500 cP orless. Also, problems typically associate with solid debris that isnormally present in organic material such as biosolids, with debris suchas plastic and hair, are eliminated as all such material is hydrolyzedas well.

The low viscosity material of the invention has a substantiallydecreased energy requirement for transportation and processing ascompared with conventional materials. No biological or organic solidmaterial remains, so problems and inefficiencies commonly associatedwith solid debris clogging or otherwise blocking transport from one areato another and thereby requiring shutting down the system formaintenance are eliminated. No solids or semi-solids are present thatwould otherwise increase wear and tear on equipment and thus, shortenequipment life. Further, organic solid materials including, for example,plastic and hair, well known to cause blockages in conventionalprocessing, are completely broken down and hydrolyzed to their monomercomponents. The acid reaction hydrolyzes many polymers that may bepresent including plastics, hair, and biologically active compounds(whether naturally present or artificially created), and breaks down anddestroys many and nearly all and preferably all macromolecules andmicroorganisms that may be present. This increases the safety to processworkers and further simplifies and increases the efficiency of anycleaning or maintenance of the system that may be required periodically.This hydrolysis further increases the safety in the use of the resultantfertilizer product in comparison to other traditionalorganics-containing fertilizer products such as those made in biosolidsalkaline-stabilization processes.

Another advantage of the invention is that, because the process can beeasily contained, the need for dust and odor control apparatus isminimized. The processing steps are closed and under negative pressureand no steps are performed in open or areas exposed to the environmentor the environment of the facility. Odor control agents are preferablyadded initially, but could optionally as easily be added at any step inthe process. Alternatively, or in addition to other odor controlprocessing, the granules may be exposed to ozone during formation and/orcooling. Ozone will substantially reduce or eliminate disagreeable odorsof the fertilizer. Thus the invention is a major improvement as comparedto conventional fertilizer manufacturing practices in which a largemanufacturing facility is located as far away from communities aspossible thereby requiring that input materials be shipped over longdistances to operate the plant. A good example of this problem was thebiosolids conversion-to-fertilizer plant located in Helena, Ark. whichpracticed the manufacturing processes taught in U.S. Pat. Nos.5,984,992; 6,159,263; 6,758,879; and 7,128,880, and utilized biosolidsthat were transported all the way from New York City.

Another advantage of the invention is that, because acid and ammonia areadded in a controlled manner, the final components of the fertilizer canbe predetermined. The exact amount of nitrogen in the final product canbe regulated based on the amount of the starting materials including thebiosolids, acid, base, water, and any other components. Similarly, theexact amount of sulfur, iron, phosphate, potassium and even organicmatter can also be regulated or, if desired, eliminated from the finalproduct producing a custom-made fertilizer product. Many crops thatrequire fertilization are grown in areas known to be high in phosphate,sulfur, potassium or other elements. Fertilizing with conventionalfertilizers, although needed, typically exacerbates the contamination.Fertilizers produced by the methods of the present invention would notonly overcome such problems, but could be tailored for use inconjunction with a specific type of soil or specific need of a selecttype of crop. In addition, the process of the invention allows forsupplementation of the fertilizer during processing with additionalingredients.

Another advantage of the invention is that it is easily performed inlarge scale, with continuous processing and under automation. Nosignificant retention times are required, thus no delays, so thatprocessing continues from start to finish without interruption as can berequired when material is required to incubate for days as is common forsome types of conventional biosolids processing as in composting oralkaline stabilization processes. Also, the process is not dependent ona particular amount of material. The process of the invention isscalable to any amount of organic material. This is highly preferred atleast because most municipal regions vary in size and thus, the amountsof organics such as biosolids produced per day vary widely. Also,amounts are expected to also vary over time. Further, each step of theprocess can be performed under complete automation including accountingfor necessary variation per day and over time.

Another advantage of the invention is that it allows for co-location ofthe facilities for processing organic materials such as biosolids withthe treatment plants. Biosolids can be then taken directly from wastewater treatment plants to processing thereby minimizing transport andpotential spillage of potentially harmful compounds. Another preferredembodiment is to locate close enough to the wastewater treatment plantto be connected by a screw or belt conveyor or a biosolids pumpingsystem. Alternatively, another preferred embodiment is to locateadjacent to the wastewater plant. The goal of the present invention isto place the processing plant as close to the wastewater plant aspossible. Thus the present invention eliminates the cost oftransportation by locating the physical equipment necessary to performthe manufacturing process adjacent or close to the source of thebiosolids such as municipal wastewater treatment plants. Manufacturingplants of the invention preferably allow for adjacent storagefacilities. Again, by being adjacent, transportation logistics aresimplified or eliminated thereby reducing transportation costs of theproduct as well as the transportation costs of input organics such asbiosolids. Also, the processes of the invention have the advantage thatthey may be interfaced with other production facilities. Thosefacilities may be associated with an unrelated commercial enterprisesuch as, for example, nylon or steel production. In these two industrieshot ammonium sulfate is created as a by-product to the manufacture ofproduct. Further and more commonly, co-locating near a commercialenterprise that creates excess heat, as in a furnace, or kiln, wouldadvantageously permit the use of this excess heat by the presentinvention as in the replacement of the need for fossil fuels such asnatural gas or by the co-generation of electricity by utilization ofsaid excess heat. By co-locating a processing facility of the inventionat these types of sites, the otherwise unwanted by-products such asammonium sulfate need not be carted away, but can be directly utilizedin the manufacture of fertilizer according to the present invention.

Another advantage of the invention is that because the process minimizesthe amount of water and power (e.g. electrical) needed, and amount ofwaste byproducts formed, as compared to conventional processing,manufacturing can be sized to service the needs of the size of theparticular community in which the plant is located. This tailoringdesign allows for a biosolids processing/fertilizer manufacturing plantthat can process smaller amounts of biosolids (e.g., less than 3 tonsper hour of dewatered biosolids) or scaled up for larger plants (e.g.,up to 10 to 12 tons per hour or more). In a preferred embodiment theoptimal size is between 6 and 8 tons per hour when the biosolids arestandardized to a percent solids of 25. The amount of biosolidsprocessed per hour does depend upon the percent solids of the biosolids.As the biosolids increase in moisture the amount of biosolids that maybe processed per hour increases proportionally. This sizing featurereduces costs, allows for standardization with interchangeable equipmentand increases the efficiency of the operational logistics as well asdecreases overall liability.

Organic materials that can be processed according to the inventioninclude, but are not limited to biosolids. Types of biosolids includemunicipal biosolids, domestic septage, farm and agricultural wastes,animal manures, digested and processed animal manures, recycled biosolidfertilizers, organic biosolids, biosolids containing microorganisms, andheat-dried biosolids. Other organic materials that can be processedaccording to the method of the invention include, but are not limited topharmaceutical and laboratory processing and fermentation wastes,organic industrial wastes, microbial materials, decayed and digestedorganic materials, farm and agricultural wastes, harvested plantmaterials such as algae including blue/green algae, seaweed and otheraquatic plants and water-borne organic detritus, bacteria includingblue/green bacteria and cyanobacteria (e.g., blue/green, rust, black),slime, insects and insect biomass (e.g., body parts, manure), mold andfungi, industrial wastes and their by-products, microbial, chemical andenzymatic digests of organic products, foods, food stuffs and foodbyproducts, and combinations thereof. In addition to conventionalbiosolids, most all organic materials can be processed by the methods ofthe invention including spoiled or otherwise rotted food stuffs such as,but not limited to meats, fish and agricultural products as well asplastics, and carbon-containing household trash and recyclables.

Another advantage of the invention is that organic materials, and evencertain non-organic materials, that are otherwise difficult to disposecan be processed according to the invention as a method of turning intoa useful product what would otherwise be waste material occupying spacein a landfill or the ocean. By way of non-limiting example, algae isskimmed from the surface or otherwise collected from bodies of water foraesthetic purposes as well as for the general health of the plants andanimals that habitat the environment. Often this algae may becontaminated with natural toxins or toxic compounds absorbed ormetabolized and concentrated within the algae from the environment. Byprocessing the algae according to the methods of the invention, thealgae can be converted to fertilizer and, importantly, the toxinsdestroyed or otherwise inactivated. In addition, algae or other plantsor bacteria may be intentionally grown in or on a contaminated area andharvested to be processed according to the invention. In addition, astoxic contamination is a matter of concentration, the materialsgenerated from the processes of the invention can be added to otherprocessed materials and sufficiently diluted so as not to pose a hazard.This process of land or water reclamation can be performed with avariety of plants, bacteria and insects with the organisms collected,processed according to the invention and rendered non-toxic or otherwiseharmless. Accordingly, the process of the invention can be applied totreated or untreated soil, humus and most any biomass including cellularcomponents, sedimentary organic matter, and biotic materials.

The organic material is preferably dewatered or hydrated to a solidscontent of between 10 and 40 percent, more preferably between 20 and 30percent, and more preferably between 22 and 25 percent. The optimalsolids content of a particular organic material can also be empiricallyor experimentally determined. Organic material received for processingaccording to the invention will typically have lower solids content thanthe optimal level. Preferably, the organic material of insufficientsolids content can be adjusted to the desired concentration throughblending/mixing with ‘dry’ organic materials with a solids concentrationof 70 to 95 percent and preferably 85 to 92 percent. The ‘dry’ organicmaterials may be available through third party sources or may beproduced with the available organic material through heat drying. Heatdrying processes include heated screw conveyors, disc dryers, rotarydryers, paddle mixer/dryers, fluid bed dryers and other commerciallyavailable processes/equipment. The dried organic materials and theorganic material of insufficient solids concentration will be mixed in amixing vessel to reach the ideal solids content as determinedempirically or experimentally. The mixing vessel may be a pugmill, amixing screw conveyor, a multishaft mixer, a ribbon paddle blender, ahigh shear mixer or other commercial high viscosity slurry mixer. Lesspreferably, the organic material of insufficient solids content can beadjusted to the desired concentration by heating the material to removewater as necessary to attain the desired concentration. This can also bedone in the same heat drying equipment listed above. Organic materialsreceived for processing may need hydration and, when necessary,additional water is preferably added from water collected during othersteps of processing. This use of recycled water further adds to both theefficiency and beneficial economics of the invention.

If necessary during the intake processing, the organic material can beconditioned by injection of steam, water, and/or heat (e.g. madethixotropic) to enable or enhance flow or movement. In these initialsteps, the organic material can be blended with chemical additives suchas oxidizing agents, for the initial odor control and to prepare thebiosolids for reaction in the pressure vessel. For example, biosolidsmay be infused with black or agricultural grad phosphoric acid tominimize odors. In this example, the phosphoric acid added here willalter the final concentration of phosphate in the fertilizer product.The amount of phosphate added to the product in this step can be aslittle as 0.5 percent and as much as 6 percent. In addition to odorminimization, the phosphoric acid adds a valuable nutrient component tothe product fertilizer.

Preferably the odor control agent is added to the initial organicmaterial to be processed, although one or more odor control agents canbe added at any time during processing including during granuleformation and cooling. Preferred odor control agents include, but arenot limited to calcium ferrate, sodium ferrate, potassium ferrate,ferrous sulfate heptahydrate, rozenite, melanterite, ferric chloride,ferrous sulfate, ferrous sulfate monohydrate, hydrogen peroxide, and/orozone as well as various other salts, derivatives and combinationsthereof. The amount and type of odor control agent can be determinedempirically by one of ordinary skill in the art, but typical amountsrange from 0.01 percent by weight of the mix or of the granules, to upto 6 percent of the mix or granules, and is preferably about 0.05%,0.1%, 0.25%, 0.5%, 0.75%, 1.0%, 1.5%, or 2.0%.

The organic material, odor control agent and possibly recycle water aredelivered to a mixing vessel where they are thoroughly mixed and mayform a thixotropic paste that is pumped or easily transported. Themixing vessel may be a pug mill, a mixing screw conveyor, a multishaftmixer, a ribbon paddle blender, a high shear mixer or other commercialhigh viscosity slurry mixer. Pug-mills, blenders and mixers are mixingchambers having blade-shaped blending elements mounted on a powerfullydriven shaft or shafts that rotate at a variable but controlled speedwhich divide, mix, back-mix and re-divide the materials to be blendedmultiple times a second to yield a thorough, uniform blend with reliableconsistency.

Alternatively, the mixing vessel to reach solids concentration and themixing vessel for the conditioning with recycle water, phosphoric acid,odor control agents or other additives may be combined in a single mixerof adequate size to give desired mixing energy and time.

This mixture is heated preferably by indirect heat such as a heatedscrew conveyor, paddle mixer or disc dryer or direct heat such as steaminjection, to a temperature required for proper reaction in the nextacidification phase of the process. The required temperature isdetermined by the type and concentration of the acid used as well as thetype and concentration of the organic materials mixture. Heating themixture preferably involves continuous mixing or agitation of themixture within the mixing vessel and possibly heating of the vesselitself. Accordingly, to achieve a desired temperature of the mix, moreor less heat may be required depending in part of the materialcomposition of the vessel. Preferably heating is performed for aretention period of time that is equivalent to the time required toachieve the desired temperature or the mixture may be maintained forlonger periods of time. Preferred periods of time, which includesheating time, are between 1 and 30 minutes, more preferably between 3and 15 minutes, more preferably between 5 and 10 minutes (or anycombination of these ranges). Also, heating times may also be dependenton the amount of mixture being heated. Preferred is a heating time thatis about equivalent to the time it takes to achieve the desiredtemperature. Less preferably, heating may also be achieved throughdirect injection of steam or heated gases in a mixing vessel or pipingsystem.

To the heated mixture is added acid, in the preferred embodiment at theinlet of the first pressure vessel, creating an exothermic reaction,which thereby causes additional heating. The acid is added to themixture by direct injection into a pressure vessel or injection at thevessel inlet. In the pressure vessel the mixture is agitated orotherwise continuously mixed. The acid is at a very low pH andpreferably in the range of pH negative 4.0 to pH positive 2.0. As isknown to those skilled in the art, with a very strong aqueous acid thereare too few water molecules to disassociate the acid completely. As aconsequence, the true pH is much lower than an actual measurement. Anegative pH indicates that the pH calculation would be a negative log ofthe molarity where the molarity of hydrogen ions is greater than 1.Preferred pH values for acids utilized are, for example, pH of 2.0 orless, pH of 1.0 or less, pH of 0.8 or less, pH of negative 1.0 or less,pH of negative 2.0 or less. Preferred acids include, but are not limitedto hydrochloric acid, boric acid, hypochlorous acid, perchloric acid,carbonic acid, phosphoric acid, sulfuric acid, nitric acid, hydrofluoricacid, carboxylic acid, and derivatives, mixtures, and combinationsthereof. The amount and type of acid added is determined by one ofordinary skill in the art from the amount of organic materials beingtreated and/or the desired result, which includes but is not limited toone or more of, achieving a predetermined temperature or pressure orliquefying the mixture. In part because the organic materials areliquefied, there is little to no build-up of calcium silicate, insolublephosphate compounds or other insoluble compounds in pipes, a typicalproblem with conventional biosolids processing facilities. Addition ofthe acid causes an exothermic reaction that heats and increases thepressure of the container. This pressure which upon commencement of thereaction is at ambient may in fact be maintained at ambient or a desiredpressure throughout the acidification process by monitored or controlledventing. Alternatively, the pressure may be allowed to increase withincreasing temperature due to the exothermic heat of dilution reaction.Such pressures may reach an upper range of 60 psig by controllingventing or in the absence of venting.

Temperature of the mixture increases, preferably to or above 66° C.(150° F.) such as for example to or above 82° C. (180° F.) or 93° C.(200° F.), and more preferably to or above 104° C. (220° F.), 110° C.(230° F.), 116° C. (240° F.), 121° C. (250° F.), 127° C. (260° F.), 132°C. (270° F.), 137° C. (280° F.), 143° C. (290° F.), 149° C. (300° F.),163° C. (325° F.) or to or above 177° C. (350° F.). This acidificationmay be carried out without pressure in the reactor by permitting releaseof vessel air during acidification, however in the preferred embodimentto facilitate the transfer of the acidified mix into the second vesselthe pressure in the first or acidification vessel will be maintainedabove the pressure achieved the second vessel. The acidification processis carried out for a retention time of between 3 minutes and 30 minuteswith a preferred time of between 4 minutes and 8 minutes.

Subsequent addition of the ammonia base, preferably in a second pressurevessel, further affects the temperature of the mix, preferably raisingthe temperature to at or above 132° C. (270° F.) such as 138° C. (280°F.) or 143° C. (290° F.), more preferably to at or above 149° C. (300°F.), more preferably to at or above 154° C. (310° F.), 160° C. (320°F.), 166° C. (330° F.) or 171° C. (340° F.), and more preferably to ator above 177° C. (350° F.) such as for example to at or above 182° C.(360° F.), 188° C. (370° F.), 191° C. (375° F.), 193° C. (380° F.), 199°C. (390° F.), 204° C. (400° F.) 210° C. (410° F.), 216° C. (420° F.),221° C. (430° F.), 227° C. (440° F.) or 232° C. (450° F.). Preferablyheating is performed for a retention period of time that is equivalentto the time required to achieve the desired temperature and allowcompletion of reactions. Preferred periods of reaction time, which mayinclude exothermic heating time, are between 1 and 30 minutes, morepreferably between 3 and 15 minutes, more preferably between 5 and 10minutes, or any combinations of these ranges. Also, reacting times mayalso be dependent on the constituents and/or makeup of mixture beingreacted and/or the amount and/or type of acid added. Reactions takeplace in closed container vessels, and pressure in the headspace of thecontainer vessel increases as well. Pressures can again be regulatedwith pressure relief valves and are preferably maintained between 5 psigand 250 psig, more preferably between 30 psig and 150 psig, and morepreferably between 40 and 100 psig. Preferred pressures include, but arenot limited to 5, 10, 20, 30, 40, 50, 60, 70, 75, 80, 90, 100, 110, 120,125, 130, 140, 150, 160, 170, 175, 180, 190, 200, 210, 220, 225, 230,240 and 250 psig.

After reaction of the acid at the desired time, temperature andpressure, the acidified mixture is discharged from the acid pressurevessel and transferred to a second pressure vessel. At the secondpressure vessel, ammonia is injected to the mixture either at the secondpressure vessel inlet or directly into the second pressure vessel. Theamount and form of ammonia added is determined by one of ordinary skillin the art from the amount of acidified mixture or organic materialsbeing treated and the desired result, which includes but is not limitedto one or more of, achieving a predetermined temperature or pressure orliquefying the mixture. The addition of ammonia increases thetemperature of the mixture liberating steam which increases theheadspace pressure within the second pressure vessel. Pressures canagain be regulated with pressure relief valves and are preferablymaintained between 50 psig and 200 psig, more preferably between 75 and150 psig, and more preferably between 100 psig and 130 psig (or anycombinations of these ranges). Preferably the ammonia addition isperformed for a retention period of time that is equivalent to the timerequired to inject the ammonia and complete the ammoniation reactions.Preferred periods of time are between 1 and 30 minutes, more preferablybetween 3 and 15 minutes, and more preferably between 5 and 10 minutes(or any combinations of these ranges). Also, time to inject ammonia andcomplete the ammoniation reactions may be dependent on the amount ofacidified mixture present and/or the amount and/or form of ammoniaadded. The pH at this point is preferably from about 1.5 to about 7.5,and more preferably from about 6.0 to about 7.0.

The processes of the present invention with biosolids and others formsof organic materials produce a fertilizer that is preferably safe tohandle and work with and preferably meets and/or exceeds the minimumrequirements of a USEPA Class A biosolids. Fertilizer product ispreferably sterilized and biological and chemical contaminants are atleast partially and preferably completely hydrolyzed and biologicalagents or organisms are denatured to the point of inactivation and/ordestruction. Typical biological or chemical contaminants include, butare not limited to one or more of pharmaceutical compounds, antibiotics,hormones, hormone-like molecules, biologically active compounds,macromolecules, carbohydrates, lipids, proteins, nucleic acids, andcombinations thereof.

The present invention preferably includes a stress conditioning over apredetermined retention period that creates stress conditions that meetor exceed those associated with traditional autoclaving of materials.This autoclave effect destroys and/or inactivates or simply sterilizesthe organic material. Microorganisms in the organic material, includingfor example, bacteria, viruses, fungi, parasites, parasite eggs,bacterial and fungal spores and combinations thereof, are destroyedand/or inactivated. In addition, the processes of the invention arepreferably designed to hydrolyze macromolecules such as proteins,nucleic acids, lipids, fats, carbohydrates and combinations thereof,and/or other biologically-active substances that may be present.

At any time during the steps of the method, one or more hardening agentscan be added to the mixture. Preferred hardening agents include, but arenot limited to ferric oxides, alum attapulgite clay, industrialmolasses, lignin, ligno sulfonate, urea formaldehyde polymerizer andcombinations thereof.

At the desired time, which may be determined empirically orexperimentally, the liquid is processed into fertilizer. Preferablyprocessing involves transfer to a granulator for removal of water andformation of dried fertilizer granules. Preferred is processing in agranulator which contains 60-88 percent by weight old granules, anddrying the granules preferably with heat to greater than 90 percentsolids, and preferably 98 or 99 percent solids or greater. Preferably,water extracted from the granules is collected with a portion recycledin the steps of the process and the remainder treated for discharge.Granules are typically quite hot during the drying process and,optionally, may be allowed to cool by transfer to a cooling room orcooling apparatus. During cooling, ozone may be injected into the cooleras an odor control measure. Preferred amounts of ozone to be injectedare from 0.01% to 5% of the weight of the cooling granules, morepreferably from 0.1% to 2% and more preferably from about 0.5% to 1%.Preferably, ozone is introduced to the cooling apparatus by sparging.

Once dried and formed and optionally after cooling, the granules aresized and preferred are granule size of 0.5 mm to 4 mm. More preferredare standard fertilizer granules of about 2.8 mm and specialty “mini”granules of about 1 mm.

One or more commercially available hardening agents can be added to thegranulator. Preferred hardening agents include, but are not limited toligno-sulfonate, lignin, molasses, or a combination thereof. Granules ofgreater than 4 mm and less than 0.5 mm are recycled in the granulator.Granules of the desired size are further processed by coating with oneor more commercially available dust control agents. Preferably, granulesgreater than 4 mm are crushed and mixed with the granules of less than0.5 mm, and all is recycled in the granulator.

The invention preferably provides for both dust and odor control systemsto ensure community acceptance of the manufacturing plant and tofacilitate meeting USEPA standards as well as making the process moreefficient through the capture and incorporation of valuable nitrogen orother potential and/or fugitive plant nutrients from the processed airof the plant.

Another embodiment of the invention is the fertilizer manufactured bythe methods of the invention. The physical and chemical characteristicsof organically modified ammonium sulfate fertilizer of one preferredembodiment of the invention are listed in FIG. 4. Fertilizer fromorganic materials such as biosolids may be powdered or in blocks, or ispreferably in the form of granules that are of a predetermined size andare resistant to crushing after polishing as compared to unpolishedgranules. Further, preferred granules have a smooth exterior with fewpits or crevices and circular or oval in shape. Preferably, thefertilizer contains no or negligible detectable un-hydrolyzed polymersand preferably the polymers within the organic mixture have beenhydrolyzed including, but not limited to plastics, pharmaceuticalcompounds, antibiotics, hormones, hormone-like molecules, biologicallyactive compounds, macromolecules, carbohydrates, nucleic acids, fats,lipids, proteins, and microorganisms. Hydrolyzed polymers form monomersof the polymer that accumulate in the product and are preferably aminoacids.

The process of the invention preferably results in the production ofgranules or pellets of USEPA Class A fertilizer product of suitabledryness, hardness, and chemical quality to produce a valuable,high-nitrogen, controlled release (e.g. slow release or dual release)commercial fertilizer product that is capable of competing in thenational and international marketplace against traditional inorganicfertilizers. A commercial, high-nitrogen fertilizer preferably hasgreater than 8 percent nitrogen by dry weight of the finished fertilizerand more preferably at least 16 percent nitrogen by dry weight of thefinished fertilizer. The Class A characteristic refers to themicrobiological quality of the finished fertilizer product, which meetsthe United States Environmental Protection Agency Class Amicrobiological standards for a product containing municipal biosolidsas defined in 40 C.F.R. §503. Also, fertilizer of the present inventionmeets or exceeds this standard on the basis of the stress condition andthe retention time utilized thus ensuring that the associated USEPAVector Attraction Standards are met (90 percent solids or greater in thefinished product), that the finished fertilizer granule is optimized forminimal water content increasing hardness characteristic and eliminatingwater with respect to transportation of the finished fertilizer. Thepercent solids of the finished product are preferably greater than 92percent solids, more preferably greater than 97 percent solids, and morepreferably greater than 99 percent solids.

Biosolids treated according to the processes of the invention typicallycontain low levels of metals such as arsenic, cadmium, copper, lead,mercury, molybdenum, nickel, selenium and/or zinc. Low levels are levelsbelow what are considered harmful and less than the Exceptional Quality(“EQ”) standard for metals as published by the USEPA for productscontaining municipal biosolids. Thus, by exceeding the USEPA regulationand the hydrolyzing conditions of the hydrolyzer or pressure vessel formacromolecules (e.g., personal pharmaceutical products such asantibiotics or hormones or hormone-like substances), the resultingfertilizer is safe for use in and around farming, plants, and animalsand is exceptionally safe for handling by workers during processing,handling, distribution and sales.

As the fertilizer product produced contains both biosolids and ahigh-content of desirable nitrogen, a preferred embodiment results in avariety of specific nutrient formula fertilizers of which the followingare typical: 16-0.5-0-18-3-15 or 16-0.5-2-17-3-14(Nitrogen-Phosphorus-Potassium-Sulfur-Iron-Organics) slow releasegranular fertilizer that is at least 99 percent dry and exceeds theUnited States Environmental Protection Agency (USEPA) Class Arequirements and Exceptional Quality (EQ) Standards. The 16 percentcontrolled-release organic nitrogen component helps bind the nitrogen inthe root zone when and where it is needed. For example, the nitrogen inthe ammonium ion, because it is bound to components of the biosolids,migrates slowly through the root zone and stays available to the plantrather than being volatized or lost to the ground water below the rootzone. As a result, it may be absorbed into the plant slowly over time.

The fertilizer product may be tailored to a desirable content ofelemental components. Preferably the fertilizer has a nitrogen contentof between 6 and 20 percent, more preferably from 8 to 18 percent, aphosphate content of between 0 and 10 percent, more preferably from noneto 5 percent, a potassium content of between 0 and 5 percent, morepreferably from one to four percent, a sulfur content of between 10 and30 percent, more preferably from 15 to 20 percent, an iron content ofbetween 0 and 10 percent, more preferably from one to four percent, andan organic content of between 5 and 30 percent, more preferably from 10to 20 percent (or any combinations of these ranges).

The fertilizer product contains nitrogen in the form of ammonium ionsnon-covalently bound to organic and other chemical compounds of thefertilizer. Unlike ammonium sulfate fertilizer, the bound ammonium ionsare not all immediately released into the soil upon application.Instead, there is an immediate release of a bolus of nitrogen to thesoil that represents from about 30-60 percent of the available nitrogenof the fertilizer. This fast release is typically over a period of oneto two weeks, slower than a conventional ammonium sulfate fertilizerthat typically releases 90 percent or more of its available nitrogen tothe soil in about 5 to 10 days, but slightly faster than or equal tonitrogen release of conventional pure biosolids fertilizers. Over thesubsequent days and weeks, the bulk of the remaining nitrogen of thefertilizers of the invention gradually releases into the soil. Sun,heat, water and/or microbes in the soil act on the fertilizer and slowlybreak down the ionic bonds releasing available nitrogen to the roots ofthe plant. Preferably, the nitrogen release is about from about 1% to 5%per week, and more preferably from about 2% to 4% per week. A smallamount of nitrogen may be covalently bound to compounds of thefertilizer, and thereby remain unavailable to the plant. Preferably thisamount of unavailable nitrogen is 5% or less, more preferably 2% orless, and more preferably 1% or less of all nitrogen of the fertilizerproduct. This dual nitrogen-release profile is unavailable withconventional fertilizers.

Dual release fertilizers of the invention allow for a single applicationof fertilizer that provides a bolus of nitrogen to growing or emergingplants such as commercial crops (e.g., fruits, vegetables, grains,trees), then a continued amount preferably over an entire or part of agrowing season (e.g., see FIG. 7). This minimizes the number offertilizer applications needed per crop which provides substantiallysavings in application expenses.

Another embodiment of the invention is directed to a process formanufacture of a fertilizer with a predetermined content of one or moreof nitrogen, phosphate and/or potassium. Processing of organic materialsproceeds as described herein wherein the acid selected is of the typeand amount desired in the final fertilizer product. For example, using aset amount of phosphoric acid will result in a set amount of phosphatein the final fertilizer product. By using a particular amount ofsulfuric acid, a particular amount of sulfur will be retained in thefertilizer. By selecting the type and amount of acid, one can pre-selectthe content of the fertilizer product produced. Preferably, thefertilizer is supplemented with one or more plant nutrients added duringone or more steps of the processing. The one or more plant nutrientsinclude, but are not limited to urea, ammonium nitrate, ammoniumsulfate, monoammonium phosphate, diammonium phosphate, urea ammoniumnitrate, liquid urea, potash, iron oxide, soluble iron, chelated iron,micronutrients like magnesium, manganese, copper, zinc, molybdenum orboron, and combinations thereof.

Another embodiment of the invention is directed to a system for themanufacture of a fertilizer. The invention comprises a mixer that blendsthe organic component containing biosolids, optionally with an odorcontrol agent. The mixture is then heated either in this mixer or in aseparate heating vessel. Heating the mixture preferably involvescontinuous mixing or agitation during the addition of heat eitherthrough indirect heating, e.g., heated container walls or heated mixers,or direct heating, e.g., injection of steam or heated air. The heatedmixture is then transferred to a first pressure vessel. The pressurevessel is preferably of a construction that allows for a vigorous mixingwith continuous exothermic reaction with the conditioned acidicbiosolids paste. An agitator/mixer is incorporated into the firstpressure vessel. Optional heating elements that may be external to orinternal within the vessel may also be incorporated into the pressurevessel. Acid may be blended directly with the heated biosolids in thefirst pressure vessel or, preferably, the acid and heated biosolids arecombined in a mixing tee and together added to the pressure vessel.Within the pressure vessel heat and pressure buildup is continued for aperiod of time to form a liquid from the paste-like biosolids mix. Theliquid mix may be further treated in the same pressure vessel, orpreferably transferred to a second pressure vessel through a pipe orconduit. The mix is preferably transferred in a turbulent flow so as toprevent or minimize the possibility of biosolid material remaining inthe conduit. Also preferably, the acidified liquid mix is combined in amixing tee with the ammonia from an ammonia source, preferably liquidammonia, and together forcibly injected to the second pressure vessel.Preferably the liquid mix is forced through the conduit by pressurizedgas that is added to the system behind the liquid mixture to ensure thatall of the liquid mix has been transferred to the second vessel.Preferably the gas, which may be air or another gaseous compound ormixture, is purged by way of a relief valve in the second vessel. Withinthe second pressure vessel, the acidified and nitrogen-fortified liquidmix exothermically heats to and/or is heated to a second predeterminedtemperature and pressurized to a second predetermined pressure for asecond period of time. Preferably the ammonia source is liquefied and/orvaporized ammonia under pressure. Also preferred, is a system wherebythe first and second pressure vessels each contain an agitator or othermechanism that continually mixes the mixture. Alternatively, the firstand second pressure vessels may be the same. Following ammoniation, themixture is transferred to a pugmill or granulator wherein the steam andwater vapor is released and the ammoniated liquid is mixed withpreformed granules (commonly referred to as “recycle” to form or shapethe new fertilizer granules. These granules are then heated in a rotarydryer or fluidized bed dryer to form dried granules of the fertilizer.In a preferred embodiment, the entire reaction process is controlled bya closed loop computer control that continuously monitors and adjuststhe exothermic reaction through addition of sulfuric acid, ammonia,plant nutrients, pH adjusters and pressure control. The preferredcontrol mechanism is through adjustment of the head space pressure abovethe biosolids in this pressure vessel. The system also preferablycontains a conveyer (e.g. pump or screw conveyer, conveyer belt) fortransporting biosolids to the mixer and another pump for transportingthe blended biosolids to the first pressure vessel; a pressurized pipingsystem that transports acidified biosolids from the first pressurevessel to the second pressure vessel, ammonia into the second pressurevessel; and disperses the ammoniated liquid to the granulator. Thus, theentire process is carried out without the need for stopping thecontinuous flow of biosolids into and out of the pressure vessels.

From the granulator, or incorporated with it, is preferably a rotarydryer or alternatively a fluidized bed dryer that further dries thebiosolids fertilizer to less than 1 percent water content. Upon exitingthe dryer, the biosolids fertilizer is further screened for size andseparated into product, undersize and oversize granule groups. Theundersized particles are recycled back into the entrance of the secondpug-mill. The oversized particles are sent to a hammer mill where theyare crushed and then recycled. After leaving the screening process thebiosolids fertilizer granules are processed through the rotary coolerwhere the biosolids fertilizer is cooled. Optionally, the cooler mayinclude an ozone generator that provides ozone to the coolingfertilizer. In the presence of ozone, odor-causing material complexeswith oxygen and possible other molecules present in the biosolids andsubstantially reduces or eliminates disagreeable odors. The fertilizergranules empty into the final polishing screens to remove undersizegranules or dust created in the cooling process. After processingthrough the polishing screens, the product passes through a coating drumwhere a coating agent that inhibits dusting is added. The biosolidsfertilizer is then warehoused ready for bulk shipping or subsequentpackaging. Alternatively, granules may be subject to an air polishingsystem that continuously recycles the hot air generated in the coolingprocess to the drying stage resulting in a reduction in fuel usage andwaste air for processing. The air drawn from the screens and equipmentis cleaned in a dust collector, cooled through a heat exchanger andreused as inlet air to the cooler. The heated air discharging from thecooler is again cleaned in a dust collector. The cleaned, heated air isused as inlet air for the rotary dryer. The system also preferablycontains one or more screens for selecting granules of a predeterminedsize and a rotary cooler for cooling and polishing the sized granules.The system of the invention preferably comprising a dust controlapparatus such as, for example, vacuums and baghouses that collect dustfrom the granulator and also a water recovery system whereby waterextracted from biosolids during processing is recovered and recycledrendering the system very efficient.

In a preferred embodiment, process air is acid scrubbed to remove anyfugitive odorants and especially vaporized or gaseous ammonia. Thecaptured ammonia, as an ammonium salt is mixed back into the biosolidsmix prior to its entering the reaction vessel or mixer therebyincreasing the efficiency of the entire system and maximizing the finalnitrogen concentration in the finished fertilizer. Miscellaneousresiduals including dust, non-specification or reclaimed product anddried fertilizer that is too small or undersized or oversize materialthat is crushed in a crushing or mill apparatus or may include otheradditives, e.g., iron that a customer would prefer can be added to thecomposition of the finished fertilizer are added to an optional pug-millor mixer positioned downstream from the pressure vessel or directly intothe granulator. During the granulation process, a hardener or hardenerswhich help to agglomerate the mix and contribute to the hardness of thedried pellet or granule are added at the second pug-mill or granulator.The hardener or hardeners are selected from the group comprised ofattapulgite clay, lignin, industrial molasses, and alum among others ormixtures of these hardeners as known by one skilled in the art.

Optionally, dependent upon the requirements of the customer, additionalplant nutrients, for example, potash or other forms of potassium, e.g.,potassium hydroxide, are preferably added at the pug mill or granulator.The solid nutrients that may be added also comprise urea, ammoniumnitrate, mono-ammonium phosphate, diammonium phosphate, zinc chloride,and/or potash. Also added in this second pug-mill is any additional ironrequired. The iron contributes an important and valuable plant nutrientto the fertilizer mix.

Also, additional ammonia may be sparged into the pug-mill and into thegranulator directly to complete the formation of the ammonium salt andto control the pH of the mix and to facilitate the formation of thefinished granule. The solids used to adjust the pH may also beprincipally alkaline agents selected from the group comprised of calciumcarbonate, sodium hydroxide, calcium oxide, cement kiln dust, lime kilndust, Class C fly ash, Class F fly ash, multistage burner ash, alum,alum biosolids from water treatment and wood ash. These are added viascrew conveyors at specific rates for each compound. The liquidadditions also include pH adjustment materials such as acids, e.g.,phosphoric acid or sulfuric acid, or caustic solutions, e.g., sodiumhydroxide. These are pumped at respective rates to the injection ring toenter the pug-mill.

The fertilizer product of the present invention preferably has a pH ofbetween 5.0 and 7.0, more preferably between pH 5.8 and pH 7.0, and morepreferably between pH 6.2 and pH 6.9. The remainder of the processingfor shaping as in pellet or granule production includes standardfertilizer granulation technology especially for high volume throughputplants. The pellet or granule product, especially in smaller throughputplants considered to be those of less than 25 tons of product productionper day, may involve more innovative technologies such as injection orextrusion followed by milling or spherulizing the pellet or granule orinvolves simple discharge from a granulator or granulating pug-mill.When a granulator or granulating pug-mill is used, it is preferable tofeed some recycle, as in dry seed material, i.e., dry fines and finesproduced by the crusher or mill or sub-specification or reclaim materialof the fertilizer product, into the pug-mill and the granulator toadjust the percent moisture present in the mix so that agglomeration ornucleation can occur resulting in granule formation.

Other preferred embodiments comprise adjustments to the processesdisclosed herein. Embodiments incorporate a pelletizer in place of thegranulator in the process train. The pelletizer may include the dryingstep to the preferred dryness or the formed pellets may then betransferred to a dryer, preferably a fluidized bed dryer to reach thepreferred dryness. These other embodiments may also incorporateadjustments to control pH, dryness, nutrients in the product, shape,concentrations etc. to produce a plethora of fertilizers specific fordifferent plants such as roses, rhododendrons, and any other flowers,vegetables, herbs, as well as products such as cat litters. Adjustmentscan also be made according to the geographic area in which the productis to be applied, to vary, for example, nutrients that may be inherentlyor otherwise missing in the location. Examples of such variationsinclude the addition of calcium, potassium or phosphorus in differentamounts.

Normal drying for final drying is conducted using a horizontal fluidizedbed dryer, or a rotary drum dryer. The dried pellets or granules whichare greater than 92 percent solids and preferably are greater than 95percent solids and more preferably are greater than 98 percent and evenmore preferably are greater than 99 percent solids are then sizedthrough one or more screens. The specification size may be varieddependent upon customer requirements, however, the range of suitableproduct for sale is between 0.5 mm and 4 mm with the commercial rangefor normal sized fertilizer is between 2 mm and 3 mm. The presentinvention also can manufacture a minimal sized product suitable for usein golf course applications which ranges from 0.5 mm to 1.3 mm. Theproper sized material is separated and then cooled and then coated andthen cooled in an apparatus, preferably a rotary drum, to less than 60°C. (140° F.), preferably to less than 49° C. (120° F.) and morepreferably to less than 43° C. (110° F.). Cooling the granule or pelletoptimally occurs in a rotary drum apparatus using ambient air or cooledair as from an ammonia evaporation cooler. Coating may occur in acoating vessel specifically for that purpose typically a rotary drum ora mixer. Alternatively, cooling and coating may be accomplished in asingle vessel which cools the material and mixes the coating agent withthe granules. Coating is with a de-duster or glazing material whichminimizes dust generation during transport, storage and application. Thefinished coated granule or pellet is then conveyed to storage asfinished high nitrogen containing bioorganic-enhanced inorganic ammoniumfertilizer until shipment from the manufacturing site. Properly coatedand dried pellets or granules have a hardness of greater than 5 poundscrush resistance in order to resist dusting and handing duringtransport, shipment and application. The de-duster coating or glazingmaterial often requires a higher temperature, often 71-105° C. (160 to220° F.), to maintain a molten condition for application in the coatingapparatus.

The granule storage facility or warehouse, usually incorporating bins orsilos to contain the granules, must be dry to prevent agglomeration ofthe granules leading to degradation and destruction. The finishedproduct is upon manufacture a sterile fertilizer having substantially nodetectable amount of viable microorganisms, such as E. coli orstreptococci, harmful to animals or humans. Substantially no viablemicroorganisms means that the fertilizer is microbially-safe and has nodetectable amount or a detectable amount well below a threshold for safehandling and use of microorganisms originating from the biosolids.Although the fertilizer is rendered sterile during manufacturing,contamination can be expected from air-borne microorganisms or bymicroorganisms deposited by animal or other contamination during storageor use. In any case, because the fertilizer product is dry andpredominantly inorganic ammonium salts will not support microorganismmultiplication at a rate which would lead to a public health problem.

During normal operations periodic shutdown plant equipment will benecessary for inspection, repair, or replacement. This is done todifferent degrees depending on specific situations. In one embodiment,shutdowns are automatic as in an automated command sequence provided bythe plant control processor; in another embodiment, the shutdowns arecarried out manually.

If a limited shutdown of the process is necessary to a single piece ofequipment the flow of biosolids into the reactor vessel would stopMaterial in the lines prior to the first pressure vessel are evacuatedinto the organic mixture mixer(s). Material in the pressure vessels andassociated piping are evacuated using alternate valve and piping systemsand air pressure to the ‘recycle’ bed of granules in the granulator orif not available to an emergency storage tank system provided for suchevents. In the pressure vessel, after the fertilizer mix drops to belowthe normal discharge point, a diverter valve on the discharge closessealing off the pressure vessel normal discharge. The diverter valve atthe bottom of the pressure vessel then shifts, allowing the compressedair entering the head space of the pressure vessel to force remainingmaterial into the return fertilizer mix line. If further cleaning isneeded, process water is then injected into the pressure vessel followedby compressed air to purge the water. Cleanout of the granulator, thedryer and all subsequent equipment is performed by running them untilthe vessels are empty.

The fertilizer of the present invention is preferably chemicallyadjusted to fit the needs of high nitrogen fertilizer requirementscontaining significant amounts of phosphate, sulfur and iron to enhancethe targeted nitrogen (N) content of between 8 and 18 percent by weight,and preferably 16 weight-percent permitting significant commercialvaluation.

FIGS. 1A, 1B and 1C, and FIGS. 2A, 2B, and 2C provide schematic diagramsof embodiments of the present invention, wherein the process of theseembodiments utilizes dewatered municipal biosolids combined withadditional plant nutrients, ammonium salt fertilizers, and bindingagents. In this example, the biosolids to be treated is a dewateredbiosolids, often referred to as a “biosolids cake.” This biosolids aredelivered to the manufacturing facility where they are stored in astorage bin until the biosolids are ready to be conditioned. Theconditioning initially takes place in a first pugmill by a vigorousmixing or blending with iron or other agent for odor control, along withoptional oxidizing agents, which converts the thixotropic biosolids intoa pumpable mix, paste, or paste-like mix. The iron and/or oxidizingagent reacts with reduced sulfur compounds and other odorants present inthe biosolids. If phosphoric acid is added to this first pugmill itassists in modifying odorants present in the biosolids and contributesthe majority of the phosphorus nutrient found in the final product. Asthe biosolids proceed through the equipment train additional plantnutrients can be infused into the mix. In this embodiment biosolids areheated during their passage through the pugmill prior to being pumped tothe first reaction vessel. In the preferred embodiment shown here twosulfuric acid streams (in a concentration range of 68 percent up to 105percent sulfuric) are injected into the vessel where in the mix isacidified and liquefaction commences. Once the mix exits the firstpressure vessel it is transferred under pressure into a second pressurevessel where the primary nitrogen infusion reaction occurs. In thisfigure, a sparger injects ammonia (or other nitrogen source) as a gas orliquid. This reaction in both vessels is carefully controlled tooptimize temperature, pressure, retention time, pH, and nitrogen, all ofwhich can be empirically determined based on the input biosolidmaterials and the desired output content of treated and dried biosolids.The pressure vessels include a plurality of valves and controls thatserve to automate the system. Additives can be used to control thetemperature, pressure, and pH and nutrient levels. The nitrogen sourcethat is pumped into the pressure vessel comprises a base, such asanhydrous or aqueous ammonia. A mix of biosolids and ammonium sulfateand ammonium phosphate is formed that becomes molecularly integrated inthat the ammonium ions become electrically bound to the amphotericorganic molecules from the bio solids thereby creating a slow-release orcontrolled-release nitrogen in the final fertilizer granule. Similarly,this electric bonding can occur between the sulfate and phosphate andiron molecules present in the mix thereby rendering these nutrientmolecules similarly to a slow-release or controlled release state. Thismix is maintained in a stress condition for a retention period asdetermined by its retention time (which in turn is based on the headpressure and volume as described herein) as the mix moves through thepressure vessel. The stress condition preferably includes elevatedtemperature, and/or elevated pressure. The elevated temperature isproduced partly or entirely by the exothermic reaction of thecomponents, which can increase the temperature of the mix. At thesetemperatures steam is generated from the mix. This steam is allowed toexit the pressure vessel under valve-controlled release, accomplishing apartial drying of the mix. The stress condition the biosolids undergo inthe pressure vessel and the retention period are controlled so as toresult in the production of a mix that is sterile and that containshydrolyzed macromolecules from the biosolids. Control of the stresscondition and the retention period also results in the fusion of theammonium ions formed with the organic molecules present creating anatural slow-release property for the nitrogen present, and thedenaturization and or hydrolysis of many macromolecules present in thebiosolids, such as proteins, plastics and other polymers. When suchmolecules are biologically active, this denaturization and/or hydrolysisrenders them less active or inactive thereby creating a safer mix forpublic usage or exposure. The retention time to induce the necessaryfertilizer properties and biological inactivation are controlled by thecontinuous pumping and flow of the biosolids into the pressure vessel.This continuous flow processing of the invention versus the traditionalbatch processing of older plants aids the high throughput of thisinvention. The continuous flow also minimizes the problems associatedwith clogging of the process necessitating down time to clear the clog.

The new liquid biosolids mixture flows from the pressure vessel and,optionally, is mixed with a hardening agent or agents and possiblyadditional nutrients to fine tune the fertilizer as desired. That mix isfurther treated by granulation or extrusion into granules such aspellets or other, smaller structures. The granules are dried in rotarydryer and passed through one or more screens to separate oversizedmaterials and undersized materials from proper-sized materials. Theoversized materials can be crushed in a crusher or mill. Subsequently,the undersized materials and the crushed oversized materials can berecycled to facilitate the granulation of the fertilizer mix. Theresulting proper-sized granules are then dried in rotary cooler, sized,coated, cooled and stored. When a traditional granulator is used in theshaping process, ammoniation by vaporized ammonia and recycle additionmay occur. Water removed from the mix as steam from the pressure vesseland from subsequent vessels as steam and/or water vapor may be condensedand preferably returned to the wastewater treatment plant (WWTP), or maybe treated and discharged into adjacent water resources, or into theatmosphere. Water that is retained from the capture of ammonia in theprocess emission air is returned to a process water containment vessel.For optimal odor control of the process and optimization of the odor ofthe resultant fertilizer from the present invention this process watermay be treated with 25 percent to 50 percent liquid hydrogen peroxide toeliminate most of the chemical odorants associated with this processwater before it is subsequently added to the biosolids mix immediatelyprior or in the first pugmill. Alternatively, the odorous process watercan be treated with gaseous ozone which is bubbled by diffuser throughthe process water thereby also eliminating the majority of odorantassociated with this water.

In another embodiment a series of reaction vessels may be used toaccomplish the acid/base reactions described herein. In a preferredembodiment of the present invention the sequence of two reactor vesselscan be utilized. In one optional embodiment a combination of one reactorvessel for acid reaction can be followed by an ammoniation conducted ina pipe-cross reactor. Alternatively, in another embodiment the reactionscould be carried out in the sequence of a first pipe-cross reactor foracidification of the biosolids mix followed by the ammoniation conductedin a pressure vessel. Also described is an embodiment whereby theacidification reaction is conducted in a first pipe-cross reactorfollowed by the ammoniation reaction in a second pipe-cross reactor.

Another embodiment of the present invention can have the acidificationof the biosolids mix to partly or fully occur in the first pugmill. Thepartly or fully acidified biosolids mix could then be treated byammoniation in a first reaction vessel. If the mix were partiallyacidified the acid/base reaction could then be completed in this firstvessel or the incomplete mix transferred to a second reactor vessel (orpipe-cross reactor) for completion.

Another embodiment of the invention is directed to a system for themanufacture of a product from organic materials treated in accordancewith the method of the invention as described herein. The combination ofpressure, heat and ammonia treatment destroys or otherwise inactivatestoxins and other hazardous compounds that are present in an otherwisecontaminated organic material. The resulting product may be used as afertilizer or other nutrient or support for plants and/or animals, or inanother industry such as, for example, construction or habitat creation.

The following examples illustrate embodiments of the invention, butshould not be viewed as limiting the scope of the invention.

EXAMPLES Example 1

To 900 grams of raw bio solids with a solids content of 16 percent wereadded 15 grams of process water, 38.6 grams of iron sulfate, and 21.8grams phosphoric acid. The mixture was thoroughly mixed (10 rpm) to aviscosity of about 1,250 cP, and then heated in an agitated pressurevessel to about 54° C. (130° F.) and vented to maintain atmosphericpressure of 0 psig (ambient). 411.4 grams of 93 percent sulfuric acidwere added to the heated mixture and allowed to attain maximumtemperature for 5 minutes. The temperature of the mixture rose to about104° C. (220° F.) and the vessel was vented to maintain atmosphericpressure at 0 psig. The viscosity ranged from 760 cP to 3630 cPdependent on induced shear rates.

Example 2

To 730 grams of raw biosolids with a solids content of 23.5 percent wereadded 56 grams of process water, 45.9 grams of iron sulfate, and 25.9grams phosphoric acid. The mixture was heated in an agitated pressurevessel to 54 C (130 F) and vented to maintain atmospheric pressure of 0psig. 490.1 grams of 93 percent sulfuric acid were added to the heatedmixture and allowed to attain temperature and maximum pressure for 5minutes. The temperature of the mixture rose to about 116° C. (241° F.)and the pressure to a maximum of 40 psig. At the maximum pressure, 165grams of ammonia were added and the ammoniated mixture allowed to attaintemperature and maximum pressure for 5 minutes after which thetemperature rose to 183° C. (362° F.) and the pressure rose to 111 psig.The viscosity was about 518 to 968 cP dependent on induced shear rates.

Example 3

To 720 grams of biosolids with a pH of 6.7 and a solids content of 24.5percent were added 50 grams of process water, and 47.2 grams of ironsulfate. The mixture was thoroughly mixed and then heated in an agitatedpressure vessel until reaching about 54° C. (130° F.), and a maximumpressure of 26 psig. 503.9 grams of 93 percent sulfuric acid were addedto the heated and pressurized mixture. The temperature of the mixturerose to 114° C. (238° F.) and the pressure to a maximum of 58 psig.After 5 minutes and at the maximum pressure, 170 grams of ammonia wereadded and the ammoniated mixture was allowed to attain temperature andmaximum pressure for 5 minutes after which time the temperature of themixture rose to 182° C. (360° F.) and the pressure to 109 psig. Theliquefied mixture was then sprayed into a granulator and the entiremixture was dried. The resulting mixture in the granulator containedabout 80 percent by weight of recycled fertilizer granules. Granuleswere sized to about 2 to 4 mm in size and tested for content. Granuleswere found to contain 16(N)-2(P)-0(K)-175(S)-1(Fe)-15(Org).

Example 4

To 720 grams of biosolids with a pH of 6.45 and a solids content of 23percent were added 100 grams of process water, and 146 grams of ironsulfate. The mixture was thoroughly mixed and then heated in an agitatedpressure vessel until reaching about 54° C. (130° F.), and a maximumpressure of 23 psig. 406 grams of 93 percent sulfuric acid were added tothe heated and pressurized the mixture. The temperature of the mixturerose to 111° C. (232° F.) and the pressure to a maximum of 34 psig.After 5 minutes at the maximum pressure, 166 grams of ammonia were addedand the ammoniated mixture was allowed to attain temperature and maximumpressure for 5 minutes after which time the temperature of the mixturerose to 176° C. (348° F.) and the pressure to 106 psig. The liquefiedmixture was then sprayed into a granulator and the entire mixture wasdried. The resulting mixture in the granulator contained about 80percent by weight of recycled fertilizer granules. Granules were sizedto about 2 to 4 mm in size and tested for content. Granules were foundto contain 16(N)-0(P)-0(K)-175(S)-3(Fe)-15(Org).

Example 5

To 600 grams of biosolids with a pH of 6.54 and a solids content of 23percent were added 130 grams of process water, and 158.9 grams of ironsulfate. The mixture was thoroughly mixed and then heated in an agitatedpressure vessel until reaching about 54° C. (130° F.), and a maximumpressure of 21 psig. 511.7 grams of 93 percent sulfuric acid were addedto the heated and pressurized mixture. The temperature of the mixturerose to 118° C. (244° F.) and the pressure to a maximum of 46 psig.After 5 minutes and at the maximum pressure, 183 grams of ammonia wereadded and the ammoniated mixture was allowed to attain temperature andmaximum pressure for 5 minutes after which time the temperature of themixture rose to 175° C. (347° F.) and the pressure to 107 psig. Theliquefied mixture was sprayed into a granulator and the entire mixturewas dried. The resulting mixture in the granulator contained about 80percent by weight of recycled fertilizer granules. Granules were sizedto about 2 to 4 mm in size and tested for content. Granules wereanalyzed found to contain 16(N)-0(P)-2(K)-185(S)-3(Fe)-13(Org).

Example 6

Nitrogen release profiles of the organically modified ammonium sulfateof the invention are determined in comparison to traditional, pureammonium sulfate fertilizer and pure biosolids as controls. First,ammonium sulfate is applied over sterilized sand in a laboratoryenvironment (ambient temperatures with no sun, water or soil organisms)and allowed to permeate the sand over a period of time. As can be seenin FIG. 5, about 90 percent of the nitrogen of the pure ammonium sulfatefertilizer travels through the sand within less than one week. Next,nitrogen penetration is compared between pure ammonium sulfate (AS),pure biosolids (MILORGANITE), and organically modified ammonium sulfateof the invention (VITAG). As can be seen in FIG. 6, about 90% of thenitrogen of AS is released through the sand within about one week ofapplication. In comparison, about 35 percent of the nitrogen oftraditional biosolids is released which increased to about 70 percentover two weeks where it remained. Organically augmented ammonium sulfateof the invention released about 60 percent of its nitrogen within thefirst week which increased to about 70 percent over two weeks.

Also, a theoretical nitrogen release profile is determined for thesesame three fertilizer materials in normal soil. Soil is presumed tocontain microorganisms that break down nitrogen-containing moleculesthereby releasing additional nitrogen into the soil. As can be seen inFIG. 7, ammonium sulfate again releases its nitrogen content within thefirst week. Pure biosolids release only about 30% of its nitrogen in thefirst two weeks, which gradually increases to about 90% over a period of26 weeks. However, organically modified ammonium sulfate preparedaccording to the processes of the invention releases just under 60percent of its nitrogen over two weeks which gradually increased toabout 90 percent over the next 26 weeks. Thus, organically modifiedammonium sulfate fertilizer prepared according to the processes of theinvention initially releases just over half of its nitrogen and slowlyreleases the remaining half over a period of weeks to months. Thistwo-stage nitrogen release profile (e.g., dual-release, two-steprelease, combined fast/slow release) is characteristic of thefertilizers of the invention.

Other embodiments and uses of the invention will be apparent to thoseskilled in the art from consideration of the specification and practiceof the invention disclosed herein. All references cited herein,including all publications, U.S. and foreign patents and patentapplications, are specifically and entirely incorporated by reference.The term comprising, where ever used, is intended to include the termsconsisting and consisting essentially of. It is intended that thespecification and examples be considered exemplary only with the truescope and spirit of the invention indicated by the following claims.

1. A system for the manufacture of a fertilizer comprising: a mixerconfigured to blend organic material with an odor control agent formingblended organic material; a first reaction or pressure vessel containingone or more inlets configured for the blended organic material and anacid, wherein the blended organic material is mixed with the acid andheated to a first predetermined temperature and pressurized to a firstpredetermined pressure for a period of time forming a liquid; a secondreaction or pressure vessel containing one or more inlets configured forthe liquid and an ammonia source, wherein the liquid is mixed withammonia from the ammonia source and heated to a second predeterminedtemperature and pressurized to a second predetermined pressure for asecond period of time; and a granulator wherein the ammoniated liquid ismixed with preformed granules and heated to form dried granules of thefertilizer.
 2. The system of claim 1, wherein the ammonia source isliquefied or gaseous ammonia under pressure.
 3. The system of claim 1,wherein the first and second reaction or pressure vessels each containan agitator.
 4. The system of claim 1, further comprising a screeningprocess to size fertilizer granules, and one or more cooling and coatingapparatus to reduce temperature and control dust prior to storage. 5.The system of claim 1, further comprising: a conveyer for transportingthe organic material to the mixer and another conveyer for transportingthe blended organic material to the first reaction or pressure vessel; apressurized piping system that transports acidified organic materialfrom the first reaction or pressure vessel to the second reaction orpressure vessel, ammonia into the second reaction or pressure vessel;and disperses the ammoniated liquid to the granulator.
 6. The system ofclaim 1, further comprising one or more screens for selecting granulesof a predetermined size and a rotary cooler for cooling and polishingthe sized granules.
 7. The system of claim 1, further comprising a dustcontrol apparatus that collects and recycles dust from the granulator.8. The system of claim 1, further comprising a water recovery systemwhereby water extracted from the organic material during processing isrecovered and recycled.
 9. The system of claim 1, wherein the firstreaction or pressure vessel is a pipe-cross reactor, the second reactionor pressure vessel is a pipe-cross reactor, or both the first and secondreaction or pressure vessels are each pipe-cross reactors.
 10. Thesystem of claim 1, wherein the first reaction or pressure vessel is areaction vessel and the second first reaction or pressure vessel is apressure vessel.
 11. The system of claim 1, wherein the first and secondreaction or pressure vessels are the same vessel.
 12. A system for themanufacture of a fertilizer comprising: a mixer that blends organicmaterial; one or more first reaction or pressure vessels containing oneor more inlets configured for the blended organic material and an acid,wherein the blended organic material is mixed with the acid providedthrough the one or more inlets that liquefies the organic materialgenerating both heat and pressure within the vessel; one or more secondreaction or pressure vessels containing one or more inlets configuredfor input of the liquid organic material from the one or more firstreaction or pressure vessels and an ammonia inlet from an ammonia sourcethat is added to the one or more second reaction or pressure vesselsafter the organic material has been liquefied; and a granulator whereinthe ammoniated liquid is mixed with preformed granules and heated toform dried granules of the fertilizer.
 13. The system of claim 12,wherein the preformed granules are recycled fertilizer granules.
 14. Thesystem of claim 12, wherein the ammonia source is liquefied or gaseousammonia under pressure.
 15. The system of claim 12, wherein the one ormore first and/or second reaction or pressure vessels contain anagitator.
 16. The system of claim 12, further comprising a screeningprocess to size fertilizer granules, and one or more cooling and/orcoating apparatus to reduce temperature and control dust prior tostorage.
 17. The system of claim 12, further comprising: a conveyer fortransporting the organic material to the mixer and another conveyer fortransporting the blended organic material to the one or more firstreaction or pressure vessels; a pressurized piping system thattransports the acid to the one or more first reaction or pressure vesseland/or ammonia to the one or more second reaction or pressure vessels;and disperses the ammoniated liquid to the granulator.
 18. The system ofclaim 12, further comprising one or more screens for selecting granulesof a predetermined size and a rotary cooler for cooling and polishingthe sized granules.
 19. The system of claim 12, further comprising adust control apparatus that collects and recycles dust from thegranulator.
 20. The system of claim 12, further comprising a waterrecovery system whereby water extracted from the organic material duringprocessing is recovered and recycled.